/**
 * BEEPERE1.c -- Timer Demo Program No.1
 *              (c) Charles Petzold, 1998
 */

#include <windows.h>

#define ID_TIMER 1


LRESULT CALLBACK WndProc(HWND, UINT, WPARAM, LPARAM);

int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, PSTR szCmdLine, int iCmdShow)
{
    static TCHAR szAppName[] = TEXT("Beeper1");
    HWND hwnd;
    MSG msg;
    WNDCLASS wndclass;

    wndclass.style = CS_HREDRAW | CS_VREDRAW;
    wndclass.lpfnWndProc = WndProc;
    wndclass.cbClsExtra = 0;
    wndclass.cbWndExtra = 0;
    wndclass.hInstance = hInstance;
    wndclass.hIcon = LoadIcon(NULL, IDI_APPLICATION);
    wndclass.hCursor = LoadCursor(NULL, IDC_ARROW);
    wndclass.hbrBackground = (HBRUSH)GetStockObject(WHITE_BRUSH);
    wndclass.lpszMenuName = NULL;
    wndclass.lpszClassName = szAppName;

    if (!RegisterClass(&wndclass))
    {
        MessageBox(NULL, TEXT("This program requires Windows NT!"), szAppName, MB_ICONERROR);
        return 0;
    }

    hwnd = CreateWindow(szAppName,
                        TEXT("Beeper1 Timer Demo"),
                        WS_OVERLAPPEDWINDOW,
                        CW_USEDEFAULT,
                        CW_USEDEFAULT,
                        480,
                        480,
                        NULL,
                        NULL,
                        hInstance,
                        NULL);
    ShowWindow(hwnd, iCmdShow);
    UpdateWindow(hwnd);

    while (GetMessage(&msg, NULL, 0, 0))
    {
        TranslateMessage(&msg);
        DispatchMessage(&msg);
    }
    return msg.wParam;
}

LRESULT CALLBACK WndProc(HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam)
{
    static BOOL fFlipFlop = FALSE;
    HBRUSH hBrush;
    HDC hdc;
    PAINTSTRUCT ps;
    RECT rc;

    switch (message)
    {
    case WM_CREATE:
    {
        SetTimer(hwnd, ID_TIMER, 1000, NULL);
        return 0;
    }
    case WM_TIMER: {
        MessageBeep(-1);
        fFlipFlop = !fFlipFlop;
        InvalidateRect(hwnd, NULL, FALSE);
        return 0;
    }
    
    case WM_SIZE:
    {
        return 0;
    }
    
    case WM_PAINT:
    {
        hdc = BeginPaint(hwnd, &ps);
        GetClientRect(hwnd, &rc);
        hBrush = CreateSolidBrush(fFlipFlop ? RGB(255, 0, 0) : RGB(0,0,255));
        FillRect(hdc, &rc, hBrush);
        EndPaint(hwnd, &ps);
        DeleteObject(hBrush);
        return 0;
    }

    case WM_DESTROY:
    {
        KillTimer(hwnd, ID_TIMER);
        PostQuitMessage(0);
        return 0;
    }
    }
    return DefWindowProc(hwnd, message, wParam, lParam);
}